(a) Field of the Invention
The present invention relates to a magnetic head and, more particularly, it relates to a magnetic head of the dual gap type having two magnetic gaps and capable of achieving high density recording.
(b) Prior Art
The magnetic head of the dual gap type is a kind of the magnetic heads of the multi-gap type and it has been used as the eraser head, for example. It has been well known in the field of magnetic recording theory that when the width of the second one of first and second magnetic gaps which the magnetic head of the dual gap type has is formed extremely narrow, or narrower than 0.1 .mu.m, for example, the second magnetic gap loses its recording capacity only to have reproducing capacity and its reproducing capacity is largely inferior to that of the first magnetic gap because recording magnetic field at the second gap becomes too small as compared with coercive force Hc of the magnetic recording medium.
In the case of the magnetic heads of the dual gap type, the one of the metal-in-gap type in which a thin film of ferromagnetic metal is arranged between the first and second magnetic gaps is available as the magnetic head for 8 mm VTR, for example. In the case of the magnetic head of this metal-in-gap type, azimuth loss is used, inclining the second magnetic gap relative to the first one, so as to remove false signal caused by the second magnetic gap. This false signal has been deemed as being harmful and unnecessary.
When high density recording is to be effected in digital magnetic recording, there is caused peak shift wherein the peak position of reproducing signal waveforms is shifted from the inverted space position of recording current for recording signals on the magnetic recording medium. This peak shift phenomenon is caused when a reproduced signal waveform is interfered with its adjacent signal waveforms, and when the peak position of reproduced signal waveforms is shifted because of this peak shift phenomenon, there is the possibility that the reproduced signal waveforms come out of the detecting window for synchro signals. As the result, they cannot read as correct information but error in this case, thereby disturbing high density recording.